The present disclosure generally relates to semiconductor structures, and particularly to semiconductor structures having a replacement gate electrode configured to provide enhanced electrical conductivity, and methods of manufacturing the same.
In advanced semiconductor devices, the width of replacement gate electrodes scales with the overall size of a field effect transistor. Because scaling of a work function material layer within a replacement gate electrode is limited in order to provide optimal work function values to the replacement gate electrode, scaling of the replacement gate electrode can reduce the volume in which a high conductivity metal can be present. Such a reduction in the volume occupied by the high conductivity metal causes significant increase in the overall resistance of the replacement gate electrode. High resistance of the gate electrode structure adversely impacts the performance of field effect transistors by increase in signal delay and voltage loss. Thus, a method is desired for providing low resistance to a replacement gate electrode while providing optimal levels of work function to the region in proximity to channel regions of a field effect transistor.